Arch Linux

SgPepper

Member

Registered: 2014-05-16

Posts: 20

Advanced battery optimisation ?

Hello

I own a HP elitebook 9470 laptop that run arch+lxde and windows 7. Most things work fine, but i have a power consumption issue that annoys me. In spite of all optimisations i found on the web, the power consumption is much bigger than when it runs windows 7. In the same conditons (idle, 10% brightness, no networking) :
Power consumption with windows : 6 watts (joulemeter) -> 8 hours battery life
power consumption with arch : 7.75+ wattss (powerop) -> 6hours battery life

What I did to optimize arch's power consumption :
- tried taylorchu's powerdown (removed, TLP does slightly better)
- install and manually configue TLP (i can post /etc/default/tlp if needed)
- disable ethernet, webcam, bluetooth, fingerprints in the BIOS
- install thermald EDIT : removed, seems to consume more than it saves
- EDIT : and GPU power saving in my grub kernel line :

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi='!Windows 2012' acpi_backlight=legacy pcie_aspm=force acpi_enforce_resources=lax i915.i915_enable_rc6=7 i915.i915_enable_fbc=1 i915.lvds_downclock=1 i915.semaphores=1 drm.vblankoffdelay=1 nmi_watchdog=0 intel_pstate=1"

So my question is : is there any advanced power management tool, any way to lower power consumption, anything else I can do to have better battery performance ?

I was thinking about blacklisting some modules (sdcard reader, MEI module, ...) but don't really know what happens to a blacklisted module, so i'm not sure it will save power... any tip about this ?

Thanks for reading
Quentin

EDIT : changed kernel line

Last edited by SgPepper (2014-05-17 21:19:06)

Name Taken

Banned

Registered: 2014-04-09

Posts: 113

Re: Advanced battery optimisation ?

What CPU governor are you using?

Head_on_a_Stick

Member

From: The Wirral

Registered: 2014-02-20

Posts: 9,003

Website

Re: Advanced battery optimisation ?

Blacklisting will stop the kernel loading the relevant module for any given piece of hardware picked up by udev, so it should save some power (I do this with my bluetooth, ethernet & webcam) but I don't think the differences would be much given that the hardware is not being used anyway...
Have you tried using

# powertop --auto-tune

---

Jin, Jîyan, Azadî

WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: Advanced battery optimisation ?

i915_enable_rc6=1 is actually making things less power efficient that the default since that disables rc6p and rc6pp.

SgPepper

Member

Registered: 2014-05-16

Posts: 20

Re: Advanced battery optimisation ?

Thanks for your answers !

Name Taken : My governor is powersave (I have a ivy bridge cpu) with pstate enable (in the kernel line)

Head_on_a_stick : I will try, but the tunables are already all "good" in powertop, due to TLP, so i'm afraid it won't be very useful & might conflict. I'll try and keep you updated though

WonderWoofy : I take good note of that. I've been through your posts, i'll change it to  i915.i915_enable_rc6=7 (correct me if I should just delete the kernel parameter)

again, much thanks

Head_on_a_Stick

Member

From: The Wirral

Registered: 2014-02-20

Posts: 9,003

Website

Re: Advanced battery optimisation ?

Head_on_a_stick : I will try, but the tunables are already all "good" in powertop, due to TLP, so i'm afraid it won't be very useful & might conflict. I'll try and keep you updated though

Good call --- only one power-management solution should be used at a time; try powertop's auto-tune instead of tlp & see if it offers an improvement...

---

Jin, Jîyan, Azadî

SgPepper

Member

Registered: 2014-05-16

Posts: 20

Re: Advanced battery optimisation ?

So, after some tests :
-  the "i915.i915_enable_rc6=7" seems to be pretty efficient, and saves me about 0.25-0.5 watts (so, much thanks)
- the "powerdown --auto-tune" does not seem to be a better alternative than tlp. Though, it sometimes save some 0.2 additionnal watts when i run it with tlp enabled. I don't really know that to  think about it. I'll try to see how it behaves after a while...

So with those settings, I reach 7.2 watts, which is better, but still pretty much more than windows... are there some last things that could help me balance that, or should I "deal with it" for now (and wait for what the future will bring) ?

Last edited by SgPepper (2014-05-20 07:21:32)